Heat dissipation is a major issue in the design and operation of semiconductor devices ("chips"). Too much heat can destroy the structure of a chip and affect its operation. The tight packing of chips in today's computer systems makes them even more vulnerable to damage from heat.
One approach to avoiding overheating is with the use of an active cooling device, such as a fan. Conventionally, a fan is a component of the computer system, contained in the computer chassis.
Another approach to avoiding overheating is the use of a passive cooling device, such as a heatsink. A heatsink provides a surface area from which heat can radiate. Many heatsinks have fins or some other geometry that increases their surface area. They are made from a material having good thermal conduction, such as aluminum. Some computers are designed so that the computer chassis provides a heatsink. An advantage of passive cooling devices is that no power-consuming mechanism is required; the heatsink operates by natural convection whereby warm air rises away from the heatsink and cool air flows toward the heatsink to replace the warm air.
Both fans and heat sinks present design challenges because they must be placed where they will be effective, yet not add bulk to the computer system. Also, electrical design considerations result in competition between electrical components and thermal components for the same "real estate".
Heat pipes have been used to alleviate design problems to some extent. Heat pipes are used in conjunction with heatsinks, and conduct heat away from a heat-generating component to the heat sink. A popular design of today's computers is the use of the computer chassis as a heatsink with heat pipes conducting heat from the internal components to the chassis. However, the addition of heat pipes has often resulted in increased manufacturing complexity and reduced serviceability after manufacture, because of the connections required for the heat pipes.